21
Which of these partially explains why the sky is blue? A.Small particles in the atmosphere absorb then scatter light waves that have a low frequency. B.The color of the sky is a reflection of the color of the ocean. C.Someone threw blue paint into the air and it stuck. D.Molecules in the atmosphere absorb and scatter light waves with a small wavelength.

22
Cyan is a primary pigment. What two colors of light are reflected by cyan pigment? A.Black A.Black and White B.Green and Blue C.Red and Yellow D.Red and Blue E.Green and White

23
Which two primary pigments combine to produce red? A.Red and Blue B.Yellow and Cyan C.Magenta and Yellow D.Cyan and Magenta E.Green and Yellow

24
How is pure red light different than pure green light? A.Red light has a longer wavelength B.Green light has a longer wavelength C.Blue light has a high frequency D.Red and Green light make Yellow light E.Red is a transverse wave and Green is a longitudinal wave.